From the Guidelines
Shoulder impingement is a condition where the tendons of the rotator cuff become compressed or irritated as they pass through the narrow subacromial space in the shoulder, leading to inflammation, pain, and limited mobility. This typically happens when the arm is raised, causing the acromion (a bony projection on the scapula) to rub against or "impinge" on the tendon and bursa. Impingement syndrome often develops gradually due to repetitive overhead activities, poor posture, muscle imbalances, or structural abnormalities in the shoulder. Common symptoms include pain when reaching overhead, weakness in the shoulder, and discomfort that worsens at night.
Causes and Risk Factors
The causes of shoulder impingement can be attributed to various factors, including:
- Repetitive overhead activities
- Poor posture
- Muscle imbalances
- Structural abnormalities in the shoulder According to a study published in the Journal of the American Academy of Orthopaedic Surgeons 1, the management of rotator cuff problems, including impingement, is crucial to prevent further complications.
Diagnosis and Treatment
Treatment usually begins with conservative measures, including:
- Rest
- Ice
- Anti-inflammatory medications like ibuprofen (400-800mg three times daily with food for 1-2 weeks)
- Physical therapy focusing on strengthening the rotator cuff muscles and improving scapular stability Corticosteroid injections may provide temporary relief in more persistent cases, as reported in a study published in the BMJ 1. However, the effectiveness of surgical options like subacromial decompression is still a topic of debate, with some studies suggesting that it may not be clinically effective for all patients 1.
Importance of Early Intervention
Early intervention is important as chronic impingement can lead to rotator cuff tears and more significant shoulder dysfunction. A study published in the Journal of the American College of Radiology 1 highlights the importance of MRI in detecting osseous and soft tissue abnormalities that may predispose to or be the result of shoulder impingement. Conservative treatment should be the first line of treatment, and surgical options should only be considered if conservative treatment fails after 3-6 months.
From the Research
Definition of Impingement
- Impingement, particularly in the context of the shoulder, refers to the compression of soft tissues, such as the rotator cuff tendons, between the humeral head and the subacromial arch or other surrounding structures 2, 3, 4, 5, 6.
- It is a common cause of shoulder pain and can be subcategorized into subacromial, internal, and subcoracoid impingement 2.
Causes and Mechanisms
- The causes of impingement include acromioclavicular joint arthritis, calcified coracoacromial ligament, structural abnormalities of the acromion, and weakness of the rotator cuff muscles 4.
- Mechanical impingement phenomenon as an etiologic mechanism of rotator cuff disease may be distinct from the broad diagnostic label of "impingement syndrome" 3.
- Intrinsic and extrinsic factors, such as movement-related impairments, can contribute to the development of impingement syndrome 3.
Diagnosis and Treatment
- Diagnosis of impingement syndrome typically involves a thorough history, focused physical examination, and standard radiographs, with advanced imaging such as MRI or ultrasound used as needed 2.
- Treatment options include physical therapy, anti-inflammatory medications, and injections, with surgical treatment reserved for refractory cases 2, 4.
- Conservative treatment, such as rest, ice packs, and nonsteroidal anti-inflammatory drugs, is usually sufficient for managing impingement syndrome and associated rotator cuff tears 4.